In full disclosure you can take my opinion with a grain of salt as I don't play pistol action games all that often and certainly not at a high level. I'm more of a bullseye guy, but I'll offer my thoughts anyways as I may be able to offer some insight.
Storm lake barrels are "match grade drop in" barrels. I'm almost certain they will be built to tighter tolerances than the factory barrel, but that doesn't mean too much for your individual accuracy. Your accuracy will be more dependent on how "that barrel" fits "your slide". Accuracy may or may not improve with any drop in.
Not sure if accuracy is you're ultimate goal or if you just want a new barrel? Storm Lake makes a good barrel if you just want to replace the factory unit. If you're looking for premier accuracy skip the drop in barrels all together and get a fitted barrel. With that said, there are other areas I would look to improve before I even touched the barrel such as the trigger, sights, slide to frame fit, etc.
Personally, I'm not a fan of super accurate, tight tolerances for action type shooting games. I lean more towards looser tolerances for ultimate reliability. In action shooting most of your accuracy or lack there of is dependent on the shooter rather than the equipment, imo.